<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        main {
            position: relative;
            overflow: hidden;
            display: flow-root;
            float: left;
        }

        .abs {
            position: absolute;
            height: 500px;
            background-color: gray;
            width: 100%;
        }
    </style>
</head>



<body>
    <main>
        <div class="abs">

        </div>
    </main>
</body>

</html>